Karl Marx said socialism would start in the most economically advanced country. Marx was just one member of the IWMA, which also included Bakunin, but Marx was remembered most. Thus Lenin's call to take over Russia surprised even the Bolsheviks initially. He maintained until his death that Russia was not the vanguard of worldwide socialist revolution - one reason the Comintern was formed.
China was even less in Marx's vision than China - the country was agricultural and essentially feudal, and the revolution was in the countryside led by peasants. Molotov called Mao Pugachev. Actually Mao realized Deng Xiaoping was a "capitalist roader" in 1962, and began working to sideline him in 1966, but Deng Xiaoping came to power after Mao died. Xi is very much in line with Deng Xiaoping. If you're saying Deng Xiaoping and his followers like Xi are capitalist readers then you're echoing what Mao realized in 1962 and expressed in 1966.